The coexistence of type 2 diabetes with breast cancer may result in poorer cancer-related survival due to a number of mediating factors including an alteration of tumor tissue hormonal sensitivity. Previous studies have shown that receptor status of breast tumors in diabetics may be changed; however, the mode of therapy for diabetes was usually ignored. This work presents the results of an analysis of the receptor status of breast carcinomas in 90 postmenopausal women suffering with diabetes mellitus type 2 who had been cured, for not less that 1 year prior to surgery, with different modes of antidiabetic therapy, including a dietary treatment only, sulfonylurea preparations, insulin therapy, and metformin as a monotherapy or in combination with sulfonylurea derivatives. No differences in estrogen receptors occurrence in tumor tissue were found in different treatment groups. The frequency of progesterone receptor-positive mammary carcinomas in women who were treated with metformin, irrespective of whether it was combined with sulfonylurea preparations, was significantly higher than in the sulfonylurea only group (P=0.043) and in the combined group of patients treated with either sulfonylurea or insulin (P=0.041). The exclusion of the patients who received neoadjuvant chemotherapy (24 persons) did not significantly affect the above results. The data may be used as an explanation of the distinctions in cancer characteristics and course between diabetic patients treated with either metformin or sulfonylurea derivatives and insulin.

Type 2 diabetes mellitus (DM2) is a risk factor of a number of malignancies. Therefore, it is important to identify factors linking DM2 and cancer within family units and how current treatment regimens influence the development of cancer in DM2 patients. The present case-controlled study was designed to assess DM2 prevalence among parents or siblings of (a) cancer patients who did not have diabetes (n = 77; age 59.3 ± 1.3 years) or (b) had overt (n = 197; 63.7 ± 0.6 years) or latent (n = 25; 61.5 ± 1.5 years) DM2 and (c) of female DM2 patients without cancer (n = 172; 61.7 ± 0.6 years). In the families of cancer-free DM2 women, DM2 was found to be significantly more frequent (30.8 ± 3.5%) than in families of cancer patients without diabetes (in all patients: 6.5 ± 2.8%; in female patients: 5.0 ± 3.4%). More importantly, DM2 in families of cancer-free DM2 women was more frequent than in the families of DM2 patients having mammary (9.5 ± 4.5%), endometrial (6.3 ± 4.1%) or any other cancer (in all: 15.2 ± 2.6%; in women: 12.9 ± 2.8%). Additionally, DM2 patients without cancer, who had parents or siblings with DM2, received biguanide metformin versus sulfonylurea derivatives more often than those with breast or endometrial cancer, either with or without family history of DM2. Our data indicate that familial DM2 may have a protective effect for some cancer types and that the type of anti-diabetes therapy may be a factor of influence in the associations observed.

BRCA1 gene mutation is associated with a combination of excessive aromatase activity/expression, predominantly estrogen receptor-negative phenotypes of tumors, and only scarce information about estrogen contents in body fluids. In the present work, isotope dilution capillary gas chromatography/mass spectrometry was used to study urinary excretion of estrogens, their catechol metabolites, and phytoestrogens in 22 women (11 with BCRA1 gene mutations and 11 without these mutations) in average 5.1+/-0.4 years before surgery for breast cancer. BCRA1 mutation carriers (including 3 premenopausal females) compared with respective controls showed significantly higher urinary estradiol and estrone excretion and a trend to an increased 2-OH-E2 excretion. In the subgroup of untreated postmenopausal women, BCRA1 mutation carriers showed a trend to increased estradiol and estrone excretion and to a higher value of the mean levels of all estrogen metabolites tested. The treatment after the baseline laboratory investigation of 6 women from postmenopausal group with the antidiabetic biguanide metformin for 3 months was associated with decreases in the excretion rates of 4-hydroxyestradiol, 2-methoxyestradiol, and 16-epiestriol and did not influence phytoestrogen excretion. The decrease in 2-methoxyestrogen excretion was more consistent in women without BCRA1 mutations than in BCRA1 mutation carriers. The data suggest the possibility that aromatase complex activation in BCRA1 mutation carriers is combined with increases in both, estrogen metabolism into catecholestrogens and their inactivation by methoxylation, and that metformin may affect both of these pathways.

he progenotoxic (G, generation of reactive oxygen forms in mononuclears) and hormonal (H, reactive insulinemia) effects of oral glucose, on the one hand, and the same effects of estradiol (10(-8)and 10(-5)M) in vitro on blood mononuclears (G: by comet tail length; H: by expression of AMP kinase and TNF and IL-6 secretion), on the other, were compared with consideration for the concepts on endocrine genotoxic switch-over in patients with breast cancer and endometrial cancer in remission. Coculturing of mononuclears with estradiol in general led to an increase in comet tail and was associated with a trend to more intense expression of AMP kinase and IL-6 secretion. The reaction to estradiol (primarily in a concentration of 10(-8)M) evaluated by the expression of AMP kinase and TNF secretion was more intensive than the reaction evaluated by comet tail lengths or by percentage of cells with comets in women with predominating progenotoxic effect of glucose vs. hormonal effect. This fact can be used as a landmark in search for means for optimization of the status and proportion of effects in the estrogen and glucose systems.